He decided to travel east to present a claim to Congress and seek land grants and other aid for the project.
Ultimately, however, he was unsuccessful: the railroad bill before Congress that would have provided funds for Elliott and his colleagues did not pass.
Elliott remained on the East Coast through the following spring, when he married Cornelia Blanchard on March 7, 1865, in her hometown of Weymouth, Massachusetts.
Several years later, he embarked on a similar venture under the name of the Oregon Central Railroad Company of Salem; this attempted partnership crumbled under Elliott's financial mismanagement and possible fraud, and was taken over by Ben Holladay, who turned it into the Oregon and California Railroad Company.
While in Washington in the spring of 1864, pursuing his case to Congress, he produced at least two detailed surveys of the Gettysburg and Antietam battlefields.
While the full story of how he became involved in this project is unknown, it is likely that he was given access to original surveys of temporary burial sites undertaken by officials at the times of the battles (Gettysburg in July 1863, and Antietam in September 1862).
His maps reflect and appear to draw heavily on the eyewitness work done by local officials and community members (such as David Wills of Gettysburg, who had commissioned a survey of burial locations within two weeks of the battle).